Knowledge (XXG)

Cyclotron resonance

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It is notable that the cyclotron frequency is independent of the radius and velocity and therefore independent of the particle's kinetic energy; all particles with the same charge-to-mass ratio rotate around magnetic field lines with the same frequency. This is only true in the non-relativistic
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The cyclotron frequency is also useful in non-uniform magnetic fields, in which (assuming slow variation of magnitude of the magnetic field) the movement is approximately helical - in the direction parallel to the magnetic field, the motion is uniform, whereas in the plane perpendicular to the
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For some materials, the motion of electrons follows loops that depend on the applied magnetic field, but not exactly the same way. For these materials, we define a cyclotron effective mass,
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Since the motion in an orthogonal and constant magnetic field is always circular, the cyclotron frequency is given by equality of
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magnetic field the movement is, as previously circular. The sum of these two motions gives a trajectory in the shape of a
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When the charged particle begins to approach relativistic speeds, the centripetal force should be multiplied by the
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that utilizes an oscillating electric field tuned to this resonance to add kinetic energy to charged particles.
27:, which is the classical trajectory of a charged particle (here positive charge) under a uniform magnetic field 651: 221: 798: 358: 47: 876: 696: 585: 611: 209: 880: 67: 857: 716: 868: 635: 512: 449: 39: 923: 296: 213: 38:
describes the interaction of external forces with charged particles experiencing a
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Note that converting this expression to SI units introduces a factor of the
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Effective mass (solid-state physics) § Cyclotron effective mass
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moving perpendicular to the direction of a uniform magnetic field
18: 515:. In Gaussian units, the Lorentz force differs by a factor of 1/ 421:{\displaystyle f={\frac {\omega }{2\pi }}={\frac {qB}{2\pi m}}} 452:, yielding a corresponding factor in the angular frequency: 822:
Physics by M. Alonso & E. Finn, Addison Wesley 1996.
42:, thus moving on a circular path. It is named after the 884: 571:{\displaystyle \omega ={\frac {v}{r}}={\frac {qB}{mc}}} 433:
limit, and underpins the principle of operation of the
346:{\displaystyle \omega ={\frac {v}{r}}={\frac {qB}{m}}} 23:
Diagram of a cyclotron orbit of a particle with speed
749: 719: 654: 614: 588: 528: 511:. In some cases, the cyclotron frequency is given in 461: 370: 308: 224: 151: 101: 780: 732: 683: 626: 600: 570: 490: 420: 345: 261: 190:{\displaystyle \omega _{\rm {c}}={\frac {qB}{mc}}} 189: 134: 135:{\displaystyle \omega _{\rm {c}}={\frac {qB}{m}}} 858:Calculate Cyclotron frequency with Wolfram Alpha 582:For materials with little or no magnetism (i.e. 844:Ashcroft and Mermin. Solid State Physics. pp12 491:{\displaystyle \omega ={\frac {qB}{\gamma m}}} 904: 8: 781:{\displaystyle \omega ={\frac {qB}{m^{*}}}} 911: 897: 770: 756: 748: 724: 718: 661: 653: 613: 587: 548: 535: 527: 468: 460: 395: 377: 369: 328: 315: 307: 235: 225: 223: 167: 157: 156: 150: 117: 107: 106: 100: 684:{\displaystyle \omega ={\frac {qH}{mc}}} 76: 815: 262:{\displaystyle {\frac {mv^{2}}{r}}=qBv} 935:Electric and magnetic fields in matter 519:, the speed of light, which leads to: 74:(constant magnitude and direction). 7: 865: 863: 634:, so we can use the easily measured 361:(being the cyclotron frequency) as: 833:Introduction to Solid State Physics 883:. You can help Knowledge (XXG) by 158: 108: 14: 867: 284:, and the circular path radius 1: 601:{\displaystyle \mu \approx 1} 54:Cyclotron resonance frequency 804:Electron cyclotron resonance 16:Motion of charged particles 968: 862: 706: 627:{\displaystyle H\approx B} 950:Accelerator physics stubs 636:magnetic field intensity 87: 82: 930:Condensed matter physics 799:Ion cyclotron resonance 272:with the particle mass 879:-related article is a 835:, 8th edition. pp. 153 782: 734: 685: 628: 602: 572: 492: 422: 347: 263: 191: 136: 66:is the frequency of a 32: 945:Scientific techniques 783: 735: 733:{\displaystyle m^{*}} 686: 629: 603: 573: 493: 423: 348: 264: 192: 137: 22: 747: 717: 652: 612: 586: 526: 459: 368: 359:rotational frequency 306: 222: 149: 99: 78:Cyclotron frequency 48:particle accelerator 940:Accelerator physics 877:accelerator physics 697:vacuum permeability 79: 60:cyclotron frequency 36:Cyclotron resonance 778: 730: 681: 624: 598: 568: 488: 418: 343: 259: 187: 132: 77: 33: 892: 891: 831:Kittel, Charles. 776: 679: 566: 543: 507:The above is for 486: 416: 390: 341: 323: 245: 210:centripetal force 201: 200: 185: 130: 957: 913: 906: 899: 871: 864: 845: 842: 836: 829: 823: 820: 787: 785: 784: 779: 777: 775: 774: 765: 757: 739: 737: 736: 731: 729: 728: 690: 688: 687: 682: 680: 678: 670: 662: 633: 631: 630: 625: 607: 605: 604: 599: 577: 575: 574: 569: 567: 565: 557: 549: 544: 536: 497: 495: 494: 489: 487: 485: 477: 469: 427: 425: 424: 419: 417: 415: 404: 396: 391: 389: 378: 352: 350: 349: 344: 342: 337: 329: 324: 316: 268: 266: 265: 260: 246: 241: 240: 239: 226: 196: 194: 193: 188: 186: 184: 176: 168: 163: 162: 161: 141: 139: 138: 133: 131: 126: 118: 113: 112: 111: 80: 68:charged particle 967: 966: 960: 959: 958: 956: 955: 954: 920: 919: 918: 917: 854: 849: 848: 843: 839: 830: 826: 821: 817: 812: 795: 766: 758: 745: 744: 720: 715: 714: 711: 705: 671: 663: 650: 649: 610: 609: 584: 583: 558: 550: 524: 523: 505: 478: 470: 457: 456: 405: 397: 382: 366: 365: 330: 304: 303: 231: 227: 220: 219: 206: 177: 169: 152: 147: 146: 119: 102: 97: 96: 56: 17: 12: 11: 5: 965: 964: 961: 953: 952: 947: 942: 937: 932: 922: 921: 916: 915: 908: 901: 893: 890: 889: 872: 861: 860: 853: 852:External links 850: 847: 846: 837: 824: 814: 813: 811: 808: 807: 806: 801: 794: 791: 790: 789: 773: 769: 764: 761: 755: 752: 727: 723: 704: 703:Effective mass 701: 693: 692: 677: 674: 669: 666: 660: 657: 623: 620: 617: 597: 594: 591: 580: 579: 564: 561: 556: 553: 547: 542: 539: 534: 531: 513:Gaussian units 504: 503:Gaussian units 501: 500: 499: 484: 481: 476: 473: 467: 464: 450:Lorentz factor 430: 429: 414: 411: 408: 403: 400: 394: 388: 385: 381: 376: 373: 355: 354: 340: 336: 333: 327: 322: 319: 314: 311: 288:, also called 270: 269: 258: 255: 252: 249: 244: 238: 234: 230: 205: 202: 199: 198: 183: 180: 175: 172: 166: 160: 155: 143: 129: 125: 122: 116: 110: 105: 92: 91: 86: 55: 52: 40:magnetic field 15: 13: 10: 9: 6: 4: 3: 2: 963: 962: 951: 948: 946: 943: 941: 938: 936: 933: 931: 928: 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642: 637: 581: 516: 506: 447: 439: 431: 356: 294: 285: 281: 277: 273: 271: 207: 145: 95: 71: 63: 59: 57: 35: 34: 28: 24: 641:instead of 357:Giving the 280:, velocity 46:, a cyclic 924:Categories 810:References 707:See also: 290:gyroradius 204:Derivation 772:∗ 751:ω 740:so that: 726:∗ 656:ω 619:≈ 593:≈ 590:μ 530:ω 480:γ 463:ω 435:cyclotron 410:π 387:π 380:ω 310:ω 299:is then: 154:ω 104:ω 89:CGS units 44:cyclotron 793:See also 509:SI units 84:SI units 875:This 443:helix 881:stub 295:The 58:The 62:or 926:: 699:. 645:: 608:) 445:. 437:. 292:. 912:e 905:t 898:v 887:. 788:. 768:m 763:B 760:q 754:= 722:m 691:. 676:c 673:m 668:H 665:q 659:= 643:B 638:H 622:B 616:H 596:1 578:. 563:c 560:m 555:B 552:q 546:= 541:r 538:v 533:= 517:c 498:. 483:m 475:B 472:q 466:= 428:, 413:m 407:2 402:B 399:q 393:= 384:2 375:= 372:f 353:. 339:m 335:B 332:q 326:= 321:r 318:v 313:= 286:r 282:v 278:q 274:m 257:v 254:B 251:q 248:= 243:r 237:2 233:v 229:m 182:c 179:m 174:B 171:q 165:= 159:c 128:m 124:B 121:q 115:= 109:c 72:B 31:. 29:B 25:v

Index


magnetic field
cyclotron
particle accelerator
charged particle
SI units
CGS units
centripetal force
Lorentz force
gyroradius
angular speed
rotational frequency
cyclotron
helix
Lorentz factor
SI units
Gaussian units
magnetic field intensity H
vacuum permeability
Effective mass (solid-state physics) § Cyclotron effective mass
Ion cyclotron resonance
Electron cyclotron resonance
Introduction to Solid State Physics
Calculate Cyclotron frequency with Wolfram Alpha
Stub icon
accelerator physics
stub
expanding it
v
t

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